/*
* Copyright (c) 2013-2018 Andreas Unterweger
*
* This file is part of FFmpeg.
*
* FFmpeg is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* FFmpeg is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with FFmpeg; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
/**
* @file
* Simple audio converter
*
* @example transcode_aac.c
* Convert an input audio file to AAC in an MP4 container using FFmpeg.
* Formats other than MP4 are supported based on the output file extension.
* @author Andreas Unterweger (dustsigns@gmail.com)
*/
#include <stdio.h>
#include "libavformat/avformat.h"
#include "libavformat/avio.h"
#include "libavcodec/avcodec.h"
#include "libavutil/audio_fifo.h"
#include "libavutil/avassert.h"
#include "libavutil/avstring.h"
#include "libavutil/frame.h"
#include "libavutil/opt.h"
#include "libswresample/swresample.h"
/* The output bit rate in bit/s */
#define OUTPUT_BIT_RATE 96000
/* The number of output channels */
#define OUTPUT_CHANNELS 2
/**
* Open an input file and the required decoder.
* @param filename File to be opened
* @param[out] input_format_context Format context of opened file
* @param[out] input_codec_context Codec context of opened file
* @return Error code (0 if successful)
*/
static int open_input_file(const char *filename,
AVFormatContext **input_format_context,
AVCodecContext **input_codec_context)
{
AVCodecContext *avctx;
AVCodec *input_codec;
int error;
/* Open the input file to read from it. */
if ((error = avformat_open_input(input_format_context, filename, NULL,
NULL)) < 0) {
fprintf(stderr, "Could not open input file '%s' (error '%s')\n",
filename, av_err2str(error));
*input_format_context = NULL;
return error;
}
/* Get information on the input file (number of streams etc.). */
if ((error = avformat_find_stream_info(*input_format_context, NULL)) < 0) {
fprintf(stderr, "Could not open find stream info (error '%s')\n",
av_err2str(error));
avformat_close_input(input_format_context);
return error;
}
/* Make sure that there is only one stream in the input file. */
if ((*input_format_context)->nb_streams != 1) {
fprintf(stderr, "Expected one audio input stream, but found %d\n",
(*input_format_context)->nb_streams);
avformat_close_input(input_format_context);
return AVERROR_EXIT;
}
/* Find a decoder for the audio stream. */
if (!(input_codec = avcodec_find_decoder((*input_format_context)->streams[0]->codecpar->codec_id))) {
fprintf(stderr, "Could not find input codec\n");
avformat_close_input(input_format_context);
return AVERROR_EXIT;
}
/* Allocate a new decoding context. */
avctx = avcodec_alloc_context3(input_codec);
if (!avctx) {
fprintf(stderr, "Could not allocate a decoding context\n");
avformat_close_input(input_format_context);
return AVERROR(ENOMEM);
}
/* Initialize the stream parameters with demuxer information. */
error = avcodec_parameters_to_context(avctx, (*input_format_context)->streams[0]->codecpar);
if (error < 0) {
avformat_close_input(input_format_context);
avcodec_free_context(&avctx);
return error;
}
/* Open the decoder for the audio stream to use it later. */
if ((error = avcodec_open2(avctx, input_codec, NULL)) < 0) {
fprintf(stderr, "Could not open input codec (error '%s')\n",
av_err2str(error));
avcodec_free_context(&avctx);
avformat_close_input(input_format_context);
return error;
}
/* Save the decoder context for easier access later. */
*input_codec_context = avctx;
return 0;
}
/**
* Open an output file and the required encoder.
* Also set some basic encoder parameters.
* Some of these parameters are based on the input file's parameters.
* @param filename File to be opened
* @param input_codec_context Codec context of input file
* @param[out] output_format_context Format context of output file
* @param[out] output_codec_context Codec context of output file
* @return Error code (0 if successful)
*/
static int open_output_file(const char *filename,
AVCodecContext *input_codec_context,
AVFormatContext **output_format_context,
AVCodecContext **output_codec_context)
{
AVCodecContext *avctx = NULL;
AVIOContext *output_io_context = NULL;
AVStream *stream = NULL;
AVCodec *output_codec = NULL;
int error;
/* Open the output file to write to it. */
if ((error = avio_open(&output_io_context, filename,
AVIO_FLAG_WRITE)) < 0) {
fprintf(stderr, "Could not open output file '%s' (error '%s')\n",
filename, av_err2str(error));
return error;
}
/* Create a new format context for the output container format. */
if (!(*output_format_context = avformat_alloc_context())) {
fprintf(stderr, "Could not allocate output format context\n");
return AVERROR(ENOMEM);
}
/* Associate the output file (pointer) with the container format context. */
(*output_format_context)->pb = output_io_context;
/* Guess the desired container format based on the file extension. */
if (!((*output_format_context)->oformat = av_guess_format(NULL, filename,
NULL))) {
fprintf(stderr, "Could not find output file format\n");
goto cleanup;
}
if (!((*output_format_context)->url = av_strdup(filename))) {
fprintf(stderr, "Could not allocate url.\n");
error = AVERROR(ENOMEM);
goto cleanup;
}
/* Find the encoder to be used by its name. */
if (!(output_codec = avcodec_find_encoder(AV_CODEC_ID_AAC))) {
fprintf(stderr, "Could not find an AAC encoder.\n");
goto cleanup;
}
/* Create a new audio stream in the output file container. */
if (!(stream = avformat_new_stream(*output_format_context, NULL))) {
fprintf(stderr, "Could not create new stream\n");
error = AVERROR(ENOMEM);
goto cleanup;
}
avctx = avcodec_alloc_context3(output_codec);
if (!avctx) {
fprintf(stderr, "Could not allocate an encoding context\n");
error = AVERROR(ENOMEM);
goto cleanup;
}
/* Set the basic encoder parameters.
* The input file's sample rate is used to avoid a sample rate conversion. */
avctx->channels = OUTPUT_CHANNELS;
avctx->channel_layout = av_get_default_channel_layout(OUTPUT_CHANNELS);
avctx->sample_rate = input_codec_context->sample_rate;
avctx->sample_fmt = output_codec->sample_fmts[0];
avctx->bit_rate = OUTPUT_BIT_RATE;
/* Allow the use of the experimental AAC encoder. */
avctx->strict_std_compliance = FF_COMPLIANCE_EXPERIMENTAL;
/* Set the sample rate for the container. */
stream->time_base.den = input_codec_context->sample_rate;
stream->time_base.num = 1;
/* Some container formats (like MP4) require global headers to be present.
* Mark the encoder so that it behaves accordingly.
没有合适的资源?快使用搜索试试~ 我知道了~
资源详情
资源评论
资源推荐
收起资源包目录
ffmpeg_mingw64_lib.rar (210个子文件)
ffmpeg-all.1 1.34MB
ffprobe-all.1 1.04MB
ffmpeg-filters.1 748KB
ffmpeg-codecs.1 175KB
ffmpeg-formats.1 152KB
ffmpeg.1 112KB
ffmpeg-devices.1 73KB
ffmpeg-protocols.1 64KB
ffprobe.1 41KB
ffmpeg-utils.1 35KB
ffmpeg-bitstream-filters.1 29KB
ffmpeg-resampler.1 14KB
ffmpeg-scaler.1 9KB
libswresample.3 6KB
libswscale.3 5KB
libavutil.3 5KB
libavcodec.3 5KB
libavformat.3 5KB
libavdevice.3 5KB
libavfilter.3 5KB
libavutil.dll.a 333KB
libavcodec.dll.a 152KB
libavformat.dll.a 110KB
libavfilter.dll.a 46KB
libx264.dll.a 33KB
libswscale.dll.a 22KB
libswresample.dll.a 15KB
libavdevice.dll.a 13KB
libpostproc.dll.a 7KB
transcode_aac.c 34KB
transcoding.c 22KB
muxing.c 21KB
demuxing_decoding.c 14KB
filter_audio.c 12KB
filtering_audio.c 10KB
vaapi_transcode.c 10KB
filtering_video.c 9KB
qsvdec.c 8KB
resampling_audio.c 8KB
hw_decode.c 8KB
vaapi_encode.c 7KB
encode_audio.c 6KB
remuxing.c 6KB
extract_mvs.c 6KB
avio_dir_cmd.c 5KB
encode_video.c 5KB
decode_audio.c 5KB
decode_video.c 5KB
http_multiclient.c 5KB
scaling_video.c 5KB
avio_reading.c 4KB
metadata.c 2KB
avutil-56.def 12KB
avcodec-58.def 6KB
avformat-58.def 4KB
avfilter-7.def 2KB
swscale-5.def 756B
avdevice-58.def 544B
swresample-3.def 473B
postproc-55.def 223B
avcodec-58.dll 13.99MB
avformat-58.dll 3.19MB
avfilter-7.dll 2.98MB
libx264-164.dll 2.66MB
avutil-56.dll 655KB
swscale-5.dll 532KB
avdevice-58.dll 134KB
swresample-3.dll 123KB
postproc-55.dll 123KB
ffmpeg.exe 285KB
ffprobe.exe 160KB
libvpx-1080p50_60.ffpreset 227B
libvpx-720p.ffpreset 227B
libvpx-1080p.ffpreset 227B
libvpx-720p50_60.ffpreset 227B
libvpx-360p.ffpreset 219B
avcodec.h 209KB
avformat.h 116KB
avfilter.h 41KB
opt.h 35KB
pixfmt.h 33KB
frame.h 32KB
avio.h 31KB
mem.h 23KB
hwcontext.h 22KB
swresample.h 21KB
intreadwrite.h 18KB
avdevice.h 17KB
common.h 16KB
pixdesc.h 16KB
avstring.h 14KB
hdr_dynamic_metadata.h 12KB
swscale.h 12KB
imgutils.h 11KB
log.h 11KB
buffer.h 10KB
samplefmt.h 10KB
channel_layout.h 9KB
avutil.h 9KB
hash.h 8KB
共 210 条
- 1
- 2
- 3
写程序的石头儿
- 粉丝: 63
- 资源: 15
上传资源 快速赚钱
- 我的内容管理 展开
- 我的资源 快来上传第一个资源
- 我的收益 登录查看自己的收益
- 我的积分 登录查看自己的积分
- 我的C币 登录后查看C币余额
- 我的收藏
- 我的下载
- 下载帮助
安全验证
文档复制为VIP权益,开通VIP直接复制
信息提交成功
评论0